Booster transformer



May 16, 1933. R, B GEORGE 1,909,053

BOOSTER TRANSFORMER Filed Aug. 23, 1930 :2 6g 5 1 f A m 26 5mm INVENTOR Faber/B Geo/ye.

AT'TORNEY Patented May 16, 1933 UNITED STATES PATENT OFFICE ROBERT B. GEORGE, 015 SHARON, PENNSYLVANIA, ASSIGNOR TO WESTINGHOUSE ELECTRIC & MANUFACTURING COMPANY, A CORPORATION OF PENNSYLVANIA BOOSTER TRANSFORMER Application filed August 23, 1930. Serial No. 477,451.

My invention relates to transformers and has particular relation to means for connecting and disconnecting a booster transformer to and from a power circuit under load.

When a long power line, or circuit, supplies power to widely distributed points of utilization, the voltage at the end of the line becomes excessively low during the periods when the line is transmitting a large amount of power and excessively high during the periods when the line is transmitting a comparatively small of a long power circuit.

Another object of my invention is the provision of means for connecting a boosting or regulating transformer to a power circuit when the voltage of the circuit is below a predetermined value, and disconnecting the transformer from the circuit when the voltage of the circuit is above a second predetermined value.

My invention will be better understood from the following description, when read in conjunction with the accompanying drawing, in which,

The single figure is a diagrammatic view of apparatus and circuits employed in a preferred embodiment of my invention.

Referring to the drawing, a power line or circuit is illustrated as comprising conductors 2 and 3 and having a boosting or regulating transformer 4 connected thereto for the purpose of increasing the voltage thereof. The transformer 4 comprises a primary winding 5 and a secondary winding 6 that is permanently connected in series-circuit relation to one of the conductors 3 in order to avoid interruption of service. he primary winding 5 is adapted to be connected in parallel-circuit relation to the circuit conductors 2 and 3 and to be disconnected therefrom by means of a switch 7. The operation of the switch 7 is controlled by a relay 8 in accordance with the voltage across the conductors 2 and 3 on the incoming-line side of the trans-- former 4.

The switch 7 comprises an arm 11 that is adapted to make contact with two stationary contact members 12 and 13 and is provided with a movable contact member 14 that cooperates with a stationary contact member 15. An electromagnet 16 is provided for actuating the switch 7 and a spring 17 is provided for normally holding the arm 11 in engagement with the stationary contact member 12. An impedance device 18, preferably an iron-core reactor, is connected between the stationary contact members 13 and for a purpose to be hereinafter described.

The relay 8 comprises an electromagnet 19 having an operating winding 21, a pivoted lever arm 22 and cooperating contact members 23 and 24. A biasing member 25 is provided for normally holding the contact members 23 and 24 out of engagement. The op erating winding 21 of the relay is energized in accordance with the voltage across the conductors 2 and 3 on the line side of the transformer 4 through the agency of a voltage transformer 26.

The operation of my system is as follows:

When the load on the circuit is such that the voltage across the conductors 2 and 3 is below a predetermined value, the operating winding of the electromagnet 16 is unenergized, and the spring 17 biases the switch arm 11 to the illustrated position, thereby connecting the primary winding 5 of the transformer across the conductors 2 and 3.

he primary-winding circuit extends from the conductor 2, through the winding 5, con ductor 28, the stationary contact member 12, the arm 11 and conductor 29, to the conductor 3. When the primary winding 5 is connected. to the conductors 2 and 8, it Induces a voltage in the secondary winding 6 that is vectorially added to the voltage existing across the conductors 2 and 3, thereby increasing the voltage of the line on the load side of the transformer.

As the load on the circuit is removed, the voltage of the circuit increases and, when the voltage across the conductors 2 and 3 reaches a second predetermined value,the energization of the winding 21 is suflicient to actuate the relay 8, thereby effecting engage- 5 ment of the contact members 23 and 24 to complete a circuit for energizing the operating winding of the electromagnet 16. The energizing circuit for the electromagnet lfiextends from one terminal of the voltage ductor 32, the operating winding of the electromagnet 16, conductor 33, the contact members 23 and 24 and the conductor 34, to the other terminal of the voltage transformer 26. The cnergization of the electromagnet 16 operates the switch 7 to disconnect the primary winding 5 from thecircuit and to establish a shunt circuit around the series-connected winding 6.

Should the primary winding 5 be disconnected while the series winding 6 is still energized, the load current traversing the winding 6 would induce a voltage of considerable magnitude in the primary winding 5 25 which might be sufiicient to puncture the insulation. I1 overcome this difficulty by connecting the reactor 18 across the terminals of the winding, 6'during;the momentary period when the primary winding 5 is disconnected and before the shunting, circuit is established around the series windingfi.

Whenthe switch 'Tis operated, the top of the arm 11' moves to-the. right to cause the disengagement offthe arm 11 and the station-- ary contact. member 12. Before disengagement ofithe arm,11' and the contact member 12, liowever,.the arm 11 engages the contact member 13,. thereby connecting the reactor 18in parallel circuitrelation to the winding 6; The reactor circuit may be traced from the oonductor 3,.tlirough conductor 29, the arm 11 and the contact member 13 of'the switch.7,.the-,reactor 18, the stationary contact member 15 of the switch 7 and conductor 36,.to the conductor 3. By connecting. the reactor 18 in parallel-circuit relation to the winding 6, the energy stored in the winding 6 is dissipated, thereby preventing the induction of a dangerous voltage in the primary winding. 5. After the disengagement ofthe arm:11 and the contact member 12, thereby; disconnecting the primary winding 5 from the circuit, the movable contact member 14-comes into engagement with the stationary contact. member 15,. thereby short circniting the reactor 18 and establishing a shuntcircuit to short. circuit the series winding 6. The series-winding, shunt circuit may, be traced from conductor 3, through conductor-29, the arm 11 and, thecontact members 14 and 15 ofthe switch 7 andconductor 36, to the conductori3,

When lthenvoltage. across the conductors 2 and.3 againfalls below the loweri predeter- 65 mined value, the operating winding of the transformer 26, through conductor 31, conelectromagnet 16 is deenergized, and the 7 spring 17 again biases the switch 7 to the illustrated position. The sequence of operation is the reverse from that previously described, that is to say, when the shunt circuit is removed from the series winding 6, the reactor 18 is connected in parallel-circuit relation thereto, and, after the parallel winding 5 is connected across the conductors 2 and 3,- the reactor circuit is interru ted.

Since modifications may e made in the apparatus and circuits described without departing from the spirit of my invention, I do not wish to be limited otherwise than by the scope of the appended claims.

I claim asmy invention:

1. In combination, two power conductors, two inductively related windings, one of said windings being connected in series-circuit relation to one of said conductors, and means for connecting the other winding between said two conductors when the voltage across said conductors falls below a predetermined value and for disconnecting the last named winding and shunt-circuiting the series-connected winding when the voltage across the conductors rises above a second predetermined value.

2. In combinations, power conductors, two inductively related windings, one of said windings being connected in series-circuit relation to one of said conductors, means for connecting. the other winding, in parallel-circuit relation to said conductors when the voltage across said conductors falls below a predetermined value and for disconnecting the parallel-connected winding and shunt-circuiting the series-connected winding when the voltage across the conductors rises above a second predetermined value and'means for preventing abnormalinduced voltages in the parallel-connected winding when it is dis connected from one or more of the conductors.-

3. In combination, an electric circuit, two inductively related windings, one of said windings being connected in series-circuit relation to said cincuit and the other winding beng connected in parallel-circuit relation to said circuit, means for disconnecting the parallel-connected winding from the circuit and: shunt-circuiting the series-connected winding, and means for preventing the induction of abnormal voltages in the parallel connected winding when it is disconnected from the circuit.

4. Incombination, power conductors, two inductively related windings, one of said windings being connected in series-circuit relation'to one of said conductors, means-for connecting the other winding in parallel-circuitrelation to the conductors when the voltage of the conductors falls below a predetermined value and disconnecting itfrom at least one of said conductors when the voltage of the conductors rises above a second predetermined value, means for establishing a shunt circuit around said series-connected winding when the parallel-connected winding is disconnected, and means for preventing the generation of abnormal voltages in the parallel-connected winding when it is disconnected and the series-connected Winding is energized, all of said transition means being controlled by a single means that is responsive to the voltage across the conductors.

5. In combination, power conductors, two inductively related windings, one of said windings being connected in series-circuit relation to one of said conductors, the other winding being connected in parallel-circuit relation to the conductors, means for disconnecting the parallel-connected winding from one or more of the conductors when the voltage of the conductors rises above a predetermined value and shunt-circuiting the seriesconnected winding after the disconnection of the parallel-connected winding, and means for preventing the generation of abnormal induced voltages in the parallel-connected winding after it is disconnected and before the series-connected winding is shunt-circuited.

6. In combination, power conductors, two inductively related windings, one of said windings being connected in series-circuit relation to one of said conductors, means for connecting the other winding in parallelcircuit relation to the conductors when the voltage of the conductors falls below a predetermined value, means for disconnecting the parallel-connected winding from at least one of the conductors when the conductor voltage rises above a second predetermined value, means for establishing a shunt circuit around said series-connected winding after the parallel-connected winding is disconnected, and opening said shunt circuit before said winding is connected in parallel-circuit relation to the conductors, a current-limiting reactor, means for connecting said reactor in parallel-circuit relation to the series-connected winding when the shunting circuit is open and the parallel-connected winding is disconnected.

7. In combination, power conductors, two inductively related windings, one of said windings being connected in series-circuit relation to one of said conductors, means for connecting the other winding in parallelcircuit relation to the conductors when the voltage of the conductors falls below a predetermined value, means for disconnecting the parallel-connected winding from one or more of the conductors when the voltage of the conductors rises above a second predetermined value, means for establishing a shunt circuit around said series-connected winding after the parallel-connected winding is disconnected and opening the shunting circuit before said winding is connected in parallelcircuit relation to the conductors, a currentlimiting reactor, means for connecting said reactor in parallel circuit relation to the series-connected winding when the shunting circuit is open and the parallel-connected Winding is disconnected, a single means for controlling the connection and disconnection of the windings and the insertion of the reactor, said control means being responsive to variations in the voltage of the conductors. 8. In combination, power conductors, two inductively related windings, one of said windings being connected in series-circuit relation to one of said conductors, contact members for connecting the other winding in parallel-circuit relation to the conductors when the voltage thereof falls below a predetermined value and disconnecting the parallel-connected winding when the voltage of the conductors rises above a second predetermined value, a current-limiting reactor, contact members for connecting the reactor in parallel-circuit relation to the series-connected winding before the parallel-connected winding is disconnected, contact members for short circuiting the reactor and the series-connected winding after the parallel winding is disconnected, all of said contact members being actuated by a single means, and means responsive to the voltage of the conductors for actuating the single means.

In testimony whereof, I have hereunto subscribed my name this 18th day of August ROBERT B. GEORGE. 

